# CVE-2026-8630 — EmilStenstrom justhtml

> As of 2026-08-23, CVE-2026-8630 is a MEDIUM-severity vulnerability in EmilStenstrom justhtml, CVSS v3.1 6.1, EPSS 0.1% (8.4th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-8630 as of 2026-08-23; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-08-23

## What is CVE-2026-8630?

justhtml before 1.12.0 (versions and . When a DOM tree is processed by sanitize_dom() using a custom policy that keeps these elements, text nodes inside them are serialized literally without escaping, allowing attacker-controlled text containing the matching closing tag sequence to break out of the raw-text context and inject arbitrary HTML into the serialized output. The default sanitization policy is not affected because it drops the contents of style and script.

The record classifies CVE-2026-8630 under weakness class [CWE-79](https://intel.threadlinqs.com/cwe/CWE-79). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 43 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.1 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **CVSS v4.0 base score:** 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 8.4% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-23

## Is CVE-2026-8630 being exploited?

It currently carries a trending score of 32 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [EmilStenstrom](https://intel.threadlinqs.com/vendors/emilstenstrom): justhtml

## How to fix CVE-2026-8630

No vendor patch reference has been recorded for CVE-2026-8630 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-8630

No threat campaign in the Threadlinqs corpus currently references CVE-2026-8630, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-08-24.

**Vendor advisory and patch**

- [github.com — vendor advisory](https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-qvc2-mg72-jjhx)

**Third-party advisory**

- [vulncheck.com — third party advisory](https://www.vulncheck.com/advisories/justhtml-before-mutation-xss-via-raw-text-elements)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-8630
Full detection coverage and IOCs for threats exploiting CVE-2026-8630 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp